Drainage basin scale sudden drought accurate identification method

Abstract

The invention discloses a drainage basin scale sudden drought accurate identification method, and belongs to the technical field of drought forecasting and early warning. The drainage basin scale sudden drought accurate identification method comprises the following steps: firstly, constructing a basin VIC land surface hydrological model based on hydrometeorological observation data and geographicspace data, and obtaining a soil water content process simulated by the model through hydrological process verification; secondly, based on the highest air temperature and the soil water content, scientifically defining an accurate sudden drought identification index by adopting a strength change rate (a rapid degree index) and a short-time scale scheme; and finally, by constructing a single-sitesudden drought magnitude index and a unit time sudden drought severity and coverage area index, determining a grading standard of the basin sudden drought event. At present, there is no strict definition related to sudden drought events, and there is no sudden drought accurate identification index system. The drainage basin scale sudden drought accurate identification method can achieve the precise recognition of the sudden drought event, and provides a scientific reference basis for the improvement of the monitoring capability of the sudden drought event of the drainage basin, the avoidance of the sudden drought risk, and the guaranteeing of the grain safety.

Description

technical field

[0001] The invention belongs to the technical field of drought forecasting and early warning, and relates to a method for accurately identifying sudden droughts at the watershed scale. Background technique

[0002] Generally speaking, traditional drought events are a relatively slow-evolving hydroclimate phenomenon, because traditional droughts mainly depend on long-term (monthly or longer time-scale) changes in precipitation and evapotranspiration. However, abnormal atmospheric circulation (such as anomalous geopotential height field and water vapor flux field) on short time scales (weeks or pentads) can lead to rapid occurrence of drought events. More recently, the term "flash drought" has been used to describe these rapidly occurring drought events. For example, relatively serious outbreaks occurred in the south-central region of the United States during May-June 2012, in New Mexico in the middle and late March of 2017, in Virginia in the United States du...

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